Expulsion fuse



F. FARRELL.

EXPULS ION FUSE June 1 9, 1928.

Filed March 26, 1925 2 Sheets-Sheet F. FARRELL EXBULSION FUSE June 19, 192

Filed March 26, 1925 2 Sheets-Sheet 2 Qf/wa 12 $5 f/"e d 7/62/71; 1!

Patented ui'ie 19, 1928. I

UNITED STATES PATENT OFFICE.

FRED FARRELL, OF CHICAGO, ILLINOIS, ASSIGNOR TO ELECTRICAL ENGINEERS EQUIP- MENT COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

EXPULSION FUSE.

Applicationfiled March 26, 1925. Serial No. 18,500.

- the fuse may be pulled out like the blade of a disconnect switch when the circuit is opened as at the 'oil switch, for rendering the terminal of the oil switch dead.

Heretofore, it has been diflicult to remove the fuse from the trunnion bearing because the fuse was loosely mounted in. sald bearing and was not restrained. According to the present invention I provide a spring stop for the fuse so it will assume a definite angular position where it may readily be seized and removedfroln the hearing. I have also provided an improved form of eye and catch therefor by which the fuse may be removed from the trunnion bearing without danger of dropping the fuse.

In the blowing of a fuse link, such as is disclosed in said prior patent, there is a tendency for the metal of the link to spatter against the walls of the sleeve and thus lower its insulating value. This is highly objec tionable. According to my invention, I provide a jacket for the fuse link which is of such a character as to limit thetendency to spatter fused metal upon the walls of the tube and yet to be sufliciently flexible to be expelled from the sleeve by the explosion of the fuse link. Preferably I employ an asbestos jacket about the link and a porcelain sleeve for the body of the fuse. Obviously, other materials may be employed. My invention provides other incldental improvements, such as appear in the trunnion bearing and its retaining spring, the cap for the upper end of the fuse body, the stop for the upper end of the fuse body against the upper contact, and other fea-' tures. all as will appear from the following description, drawings and claims.

\Yhile the fuse. shown and described is of the expulsion type, it is to be understood that the present construction is also adaptable to fuses of any other type.

In order to acquaint those skilled in the art with the manner of practicing my invention, I shall now describe a particular embodiment of the same in connection with the accom anying drawings.

In t e drawings Fig. 1 is a side elevational View of an expulsion fuse mounted in place on its terminal support and brings out. the idea of my novel hinge arrangement and, in dotted lines, the manner of removing the fuse out of engagement with the hinge support;

Fig. 2 is an enlarged sectional view setting out in greater detail the features of the' hinge arrangement between the fuse and the lower. terminal support;

F enlarged sectional view of the taken, on line 3-3 of Fig. 1;

F1 .4is sin-enlarged sectional view taken on line Hof Fig- 1 and illustrates the novel Arrangement of the hinge spring and cams; i

Fig. 5 is a sectional view taken on line 55 of Fig. 1;

Fig. 6 is a longitudinal sectional view of an expulsion fuse of my invention; and

Fig. 7 illustrates the type of switch stick employed and the manner of using it in disconnecting the fuse from one of its terminal su ports.

o a standard base member 10 are secured insulator supports 11 and 12 on which in turn are mountedthe insulators 13 and 14. On the tops of these insulators are fitted the metal caps 15 and 16. The character of the insulators and mounting parts is not of the essence of the present invention, and may be of any standard type.

For mounting the fuse terminals to the caps 15 and 16, suitable anglebrackets 17 and 18 are provided to which are fastened the terminal members 21 and 22 by bolts 23. One of the contact terminals, designated in its entirety by the numeral 19, is made up of a pair of spring jaws 24, reenforcing plates 25 and arcing sprmgs 26. Suitable openings are provided at the lower ends in openings at their lower ends by which they may be secured to the terminal member 21.

as by the bolts 30. The spring jaws 28 are,

. respectively. An eccentric flange 36 is cast integral with one end of the block 34. The purpose in makin this-flange eccentric is to permit it to rea ily clear the contact jaws and arcing horns. A knurled thumb screw 37 is adapted to fit into a threaded opening in the eccentric portion of the flange 36. An arcuate depression 36 is provided in the ad-' jacent face of ferrule -34 to accommodate the projecting end portion of screw 37. This thumb screw serves to fasten the fuse wire 38 to the integral flange portion of the contact block. The outside edge of the flange 36 is threaded which threads are adapted to cooperate with the internal threads of the cap 39, which serves to. properly protect the upper end of the fuse and also to prevent refuse matter and gases to be shot out of this end when the fuse blows. The lower end of the contact block 34 is relatively cylindrical in form, and has on one side a ring 40 which extenls out laterally and which serves as a means by which the fuse may be swung into or out of contact with the jaws 24 as shown in Fig. 1. Opposite the integral ring portion. 40 .is the clamping por tion 42, into which is threaded the clamping bolt 43. The central portion of the block 34,

is hollow so as to permit the fuse 38 to be freely admitted therethrough That part of the hollow portion which is under the contact surface of the block 34 is relatively rectangular in form. This is also true of the contact portion of the block so as to permit of surface contact between the block and its cooperating contact jaws. From the relatively rectangular form in the contact portube 33 may be held securely in the clamping member 42 by tightening the bolt 43. The clamping member 42 is also provided with a flange portion 45 which cooperates with a stop 44 on the 'terminalmember 22 to limit the travel of this end of the fuse toward the terminal member. The stop 44 is secured in place by the bolt 23. By limiting the travel of the fuse or connecting member 32, it also serves to properly position the contact block 34 with reference to the contact jaws 24. Proper contact with the may be tightly secured to the tube 33. A

cushion seal, however, is also provided between the tube 33 and the inner wall of the clamping means 48 which is also of braided copper. The relatively cylindrical clamping portion 48 merges into a'relatively rec-,

tangular contact portion 50, which is adapted for cooperative engagement with the contact jaws 28. Centrally located on the upper side of the part 50 is an outwardly prov j ecting lug 51, in which is secured a threaded stud 52. A knurled screw 53 cooperates with the stud 52 to secure thereto the fuse wire 38 which is fastened between the brass washer 54 and the lock nut 55 on the stud 52.

Extending out laterally from the lower square portion of the contact block 35 and integral therewith, is a flat plate member 56 provided with a key-hole opening 31. Portion 50 of block 35 is provided with an arcuate recess or depression 50 disposed, concentric and in alignment with the upper portion of ke -hole opening 31, to facilitate insertion o a key member through the opening. It is by means of this opening, as willbe explained later, that member 32 may be placed on or removed from its support.

Extending downward from the contacting sides of the portion 50 are the supporting plates 57 and 58. The hollow portion of t e contact block 35 extends from the relatively circular hollow portion at the clamping end of the contact block 35 through the rectangular hollow portion in the contact part of the block and out into the space between these supporting plates. This provides an opening 59 at the lower end of the block 35, which permits all refuse matter and gases to be blown out between the supporting plates.

The lower ends of the plates 57 and 58 have pins 60 and 63 projecting from their outer faces and cams 61 and 62 opposite the pins and integral with the inner facesof the plates. The pins 60 and 63are adapted to engage with the bearing surfaces in the hinge portions of the hook-shaped members 64 and 65 and the springs 66 and 67. The hook-shaped members 64 and 65 have open slot portions 75 andlre cast integral with'- The cams 61 and 62 are adapted to cooperate with a roller member 68 on the pin 69. The pin 69 connects the hook-shaped members 64 and 65. The outer faces of the members 64 and 65 are provided with integral'lugs 70 and 71, each of which has an opening therein through which the springs 66 and 67 respectively may be freely admitted. These lugs serve to hold one end of the springs in position, the other end in each case being held inplace by the outwardly projecting pins 72 and 73. These pins are also integral with the members 64 and 65, respectively, and have openings therein in which the ends ofthe springs 66 and 67 may be inserted. From the dotted line view of the springs, as shown in Fig. 2, it will be noted that each of them is provided with a hump portion 74 which bears against the i outward projecting end of the pin 63. In

so doing, 1t serves to hold the pin against the bearings in the members 64 and so as to prevent the fuse 32 to work its way out of the slot 75 when it is being swung back into position after renewal.

A spring bumper arm 76 serves to limit the downward travelof the fuse when it is swung out and into open osition not only to re ace the impact of t e fuse. dropped downwardly, but more essentially to hold the fuse in the inclined position shown in dotted lines in Fi 1 where the keyhole slot 31 will be hel definitely in such a position that the operator may easily insert the key 84 on the stick 81. Thus the fuse is held definitely in position by its weight tending to rotate it in the counter clockwise direction, as viewed in Fig. 1, and the spring pressure tending to push against it in a clockwise direction, as viewed in Fig. 1.

Free .swin ing of the fuse is thereby prevented and, at the same time, the inclined position of the fuse is most advantageous and suitable for easy cohplin ofthe coupling members 84 and 31. T1118 spring arm is secured to the terminal 21 b means of the bolts 77, which also serves to asten the connecting socket 78 thereto.

As heretofore mentioned, the fuse wire'38 is surrounded by a jacket of insulating material, such as asbestos, which prevents the metal from spattering up'the inner'wall of the outer tube when the fuse blows. This 'acket, which is designated in the drawings y the numeral 80 rests u on the lower end of the fuse wire and ts rather loosely For the purpose of opening, closing on removing the fuse 32 with respect to its terminal supports, I have provided a switch stick 81 having at one end a metal cap portion 82. Integral with this cap portion 82 is an outward extending pin member 83 and an upwardly extending key member 84'. In

operation, the member 83 is adapted to cooperate with the hole in the ring 40, to

remove the fuse out of the contact terminal 19 or to swing it about the lower hinge sup:

ort into contact with the terminal 19.

he pin member 83 has a knob or enlargement at its end which provides a shoulder to keep the pin from slipping out of the eye when the operator pulls upon the handle or pole 81 in the position shownin Fig. 7. Likewise, upon swinging the fuse from its dotted line position in Fig.1 to its full line position, this knob on the pin 83 keeps the pin from slipping out of the eye too readily. The key' member 84 is adapted to cooperate with the key hole opening 31 in the plate 56. To remove the fuse from its mounting, as shown in full line position in Fig. 1, the laterally extending pin 83 of the operating handle 81 is inserted laterally into the ring 40 and then, by a quick downward jerk on the handle 81, the fuse is swung about 1 its trunnions 60 63 into the dotted line posicent the trunnion member, such as shown,"

for example, in the prior patent to Jacobs, No. 1,503,266. The difliculty, however, has been that when the operating stick is pushed upwardly to disengage the fuse from its trunnion, it often umps off of the in on the operating stick and falls to the ground and is broken.

The key shaped pin and key hole slot of my invention e ectively prevent this. When the fuse has been-swung to the dotted line position shown in Fig. 1, the key member 84 is then inserted through the slot 31 and turned by a twisting motion of the stick 81. The key member 84 comprises a central circular shank with a collar or shoulder 85 below it, and with the wing or web extending laterally at the upper end of said round shank. Hence, when the key vmember ,is turned on its round shank in the round part of the key hole slot, the web turns out of register with the slot through which it entered, and as a result the stick and the fuse are firmly secured together, so that an up ward thrust onthe stick pushes the trunister with the slot of the key hole.

until the parts are rotated relative t'o each other to "bring the web' of the key into reg- As a result of this construction, the stick and the fuse are tied together so that the fuse may,

by a rotary and axial movement of such a character as to bring the key and-key hole accurately into alignment and then withdraw the key from the key hole.

To replace the fuse after it has been removed-it is only necessary to place it. on the switch stick, so that it rests on the collar 85 the key 84 being then turned to move the web out of register with the slot in the key hole 31. It may then belifted up and placed into the openin 75'and forced past the hump in the springs 4 by means of the key member 84. When the ends of the springs 67 are resting in their bearings in the members 6& and 65, the switch stick may be removed out of the opening 31 and the portion 83 may be inserted in. the opening in the ring 40. The fuse may be then swung up and into position as shown by the full lines in Fig. 1.

' I consider that it is broadly new to connect a fuse of this character with an operating stick by means which requires rotary-motion of the .stick to connect the parts. I further believe that it is broadly new to connect the fuse and the operating stick by .means requiring first an axial and then a rotary motion. is highly practical and is the preferred construction, I do not intend to be limited to this manner of forming the connection. I do not intend to be limited to the precise details shown or described. I

I claim p 1. In a device of the class described, a contact blockhaving a screw terminal at one end, a split clamping portion at the opposite end, and a. contact portion intermediate said ends, said contact portion having fiat sides, said clamping portion having a flat abutment surface extending out laterally and disposed beyond said contact portion.

2. In a device of the class described, in'

combinatioma terminal member, a pair of contact jaws onv opposite sides of said terminal member, a pair ofreenforcing plates for said contact jaws, a pair of arcing horns on the outer faces of said'reenforcing plates,

and bolt means for securing the contactjaws, reenforcing plates and the arcing horns to the terminal member.

3. In a fuse, a sleeve of vitreous material, a ferrule therefor, said ferrule having at one end a split clamp forming a socket for the end of the sleeve, and a contact portion 'beyond the clamp providing flat contact sur- While the key and key hole slot and a stop lug at the opposite side.

- -5. In combination, a contact block having a pair ofaxially extending legs, transverse trunnions .on theends of said legs, a cam integral with one of said legs, a stationary -contact member having bearing supports with bearings adapted to receive the trunnions, a transverse member'joining said bearing supports, said cam-cooperating with said transverse member for holding the trunnions in their supports.

6. In combinationfa contact block having a split clamping portion at one end and a pair of. parallel mounting plates at the opposite end, a longitudinal opening in said contact blockhaving a fuse link extending therethrough, and means provided adjacent the contact portion of said contact block for securing said fuse link thereto said link being adapted to be expelled through said opening.

' 7. In combination, a contact block having a clamping portion at one end, and a pair of parallel mounting plates at the opposite end, the lower. end of said contact block being open to permit the fused metal to be forced outwardly.

8. In combination, a pair of terminal members, a fuse having at one -end a contact block provided with, an eye having a lateral opening and" at itsopposite end a contact block provided with an eye havin a longitudinal opening, and means adapted to cooperate with the lateral opening and with the longitudinal openin of said eyes for removing said fuse out of. contact with said terminal members.

9; In combination,- a pair of terminal members, a fuse having. at one-end a contact blockprovided with an eye having a lateral opening and at the opposite end a contact block rovided with an eye having a longitudina opening, means adapted to engage with thelateral opening in said first eye ment of said'fuse. l

,10. In combination, a terminal member,

a fuse having a contact block provided withan eye having a longitudinal opening, means adapted to engage said opening by' relatively longitudinal movement thereof, said means being adapted to be locked in said openin by relative angular motion for removal '0 said fuse out of contact with said terminal. 11. In combination, a pair of terminal members, a fuse having contact blocks at its opposite ends adapted to cooperate with said terminal members, a ring portion on,

one of said contact blocks said ring portion having a transverse opening and a portion having a longitudinal keyhole slot on the other contact block, and means adapted to cooperate with the ring on said first contact block and with the keyhole slbt in said sec-' ond contact block for removing said fuse out of contact with said terminal members. 12. In combination, a pair of terminal members, a fusehaving contact blocks at its opposite end, a ring with transverse opening integral with one of said contact blocks, a portion having a longitudinal ke hole slot therein on the other contact bloc means adapted to engage with said ring for swinging said fuse out of contact with one of said terminal members, and means adapted to engagewith the keyhole slot in said portion onsaid second contact block for removing said fuse out of contact with said second terminal member.

13. In combination, a terminal member, a contact block having a laterally extending portion provided with a longitudinally extending keyhole slot for cooperating with said terminal member, and means adapted.

to engage with said keyhole slot for moving said contact block into and out of contact with said terminal member.

' 14. In combination, a terminal member,

a contact block having'a laterally extending portion provided with a longitudinal opening keyhole slot, means adapted to engage -with said keyhole slot for moving said con- I members fastened thereto, one of which ex-,

tact block into and out of contact with said terminal member, said means comprising a switch stick having a key member extending longitudinally of the stick. p

'15. A switch stick having a pair of finger tends out laterally and the otherlongitudi nally relative said switch stick said latter finger comprising a key member having a lateral win at its upper end.

16. A switch stick having a pair of finger members secured thereto, one of which ex-- plates and on the outer sides thereof, a cam integral with one of said plates, a terminal member having supports adapted to receive the bearing pins of said contact blocks, and

having a transverse opening and having a pair of supports, a contact block provided with a laterally extending portion aving a longitudinally extend' keyhole slot therein, bearing pins on contact block adapted for movement with said supports, means for constrainin the movement of said bearing pins in sai supports, and key means adapted to coo rate with the keyhole slotin said integra portion for removing said contact block out of said supports against the force of said constraining means. i

20. In combination, a terminal member, a contact block ada ted for cooperation with said terminal mem r, a clamping portion for said contact block having a laterally extending flange, an abutment post on said terminal member, said abutment post being adapted to cooperate with said flange for limiting the travel of said contact block in spring contacts, open trunnion bearings ad jacent one of said contacts, a fuse member having trunnions at its lower end seated in said bearings, said fuse member having contact portions co-operating with said spring contacts, eye members on said fuse adjacent said contact portions, the upper eye member having a transverse opening and being mounted on the front side of said trlmnion, and the lower eye member having a longitudinal opening and being disposed on the back side of said trunnion member when the fuse is mounted in the spring contacts.

22. In combination, a pair of insulated spring contacts, open trunnion bearings adjacent one of said contacts, a fuse member having trunnions at its lower end seated in said bearings, said fuse member having con tact portions co-operating with said spring contacts, eye members on said fuse adjacent said contact portions, the upper eye melpeaber mg mounted on the front side of said trunnion, and the lower eye member having a lon itudinal opening and being dis osed on t e back side of said trunnion-mem fuse is mounted in the spring contacts, and a buffer member for holding the fuse inclined downwardly and outwardly to hold r when the v the longitudinal opening in the lower eye 'on the front side of said trunnion, and the lower e e member having a longitudinal opening an being disposed on the back side of said trunnion member when the fuse is mounted in the spring contacts, and an operating stick having a transversely extending finger for hooking into the first eye to swing the fuse about its trunnions downwardly,

and a longitudinally extending finger for co-operation with the lower eye member, said longitudinally extending finger and said low er eye having interfitting parts requiring relative longitudinal and rotary motion to couple the same together.

24.111 combination, a pair of insulated spring contacts, open trunnion bearings adjacent one of said contacts, a fuse member having trunnions at its lower end seated in said bearings, said fuse member having contact portions co-operating with said spring contacts, eye members onsaid fuse adjacent said contact portions, the upper eye member having a transverse opening and being mounted on the front side of said trunnion, and the lower eye member having a longitudinal opening and being disposed on the back side of said trunnion member when the fuse is mounted inthe spring contacts, and a buffer member for holding the fuse inclined downwardly and outwardly to hold the longitudinal opening in the lower eye member in readily accessible position to be engaged by a longitudinally extending finger for removing the same from the bearings, and an operating stick having atransversely extending finger for hooking intothe first eye to swm 7 the fuse about its trunnions downward y, and a longitudinally extending finger for co-operation with the lower eye member, said longitudinally extending finger and said lower eye havin interfittingparts requiring relative longitudinal and rotary motion to couple the same together.

25. In combination, a fuse having trunnions, stationary bearings for saidtrunnions open at the top, an operating stick for removing said fuse from itsbearings, said fuse and said stick having co-operating and interfitting members requiring relative longitudinal and rotary motion tocouple the same together.

26. The combination of a fuse having a longitudinal sleeve of insulation, contact members on the ends thereof, and a transversely projecting ring secured to the fuse structure and having a key hole slot therein fuse from a support therefor.

. 27 The combination of a fuse having a longitudinal sleeve of insulation, contact members on the ends thereof, a transversely projecting ring having a key hole slot therein opening longitudinally of said fuse, and an operating stick having a prong provided with a lateral web and being adapted to be projected through the key hole opening in said ring. r

28. In combination, a pair of spring terminal members, bearing brackets adjacent one of said members, said brackets having open bearings therein, a fuse having contact portions co-operating with said terminal members and having trunnions adapted to be mounted in said bearings, and an eye adjacent said trunnions, said eye comprising a key hole' slot opening longitudinally of the fuse.

29. In combination, a fuse having a sleeve of insulation, metal contact ferrules on said sleeve, one of said ferrules having an eye with a longitudinally extending key hole slot,

and a stick having a longitudinally extending prong, said prong having a cylindrical stem with a shoulder below the stem, and a lateral wing formed above thestem, said prong extending through said key hole and said eye being held between said Wing and said shoulder.

30. In combination, a fuse having trunnions, stationary bearings for said trunnions open in the direction of the axis of the fuse, an operating stick for removing said fuse from its bearings, said stick and the fuse having cooperating quick acting means for coupling the fuse and'thestick together, said means positively preventing detachment of the fuse from the stick when in operative position.

31. In combination, a fuse having trunnions, stationary bearings for said trunnions open at the top, an operating stick for removing said fuse from its bearings, said stick and the fuse having cooperating coupling members requiring relative longivent relative upward movement of the fuse when removed.

33. In combination, a fuse having trunnions, stationary bearings for said trunnions open in the direction of the axis of the fuse, an operating stick for exerting upward pressure on the fuse for removing it from its bearings, yielding means projecting across the tops of the bearings and releasably holding the trunnions against upward movement out of the bearings, the stick and the fuse having cooperating coupling means acting to prevent relative upward movement of the fuse when released.

34. In combination, a fuse having trunnions, stationary bearings for said trunnions open at the top, a buffer below the bearings disposed to support the fuse in open position and at a downward inclination, a stick havmg an operating member extendi therefrom, and a member carried by the use and disposed for rece tion of said operating member when the se is in open position.

35. In combination, a fuse having trunnions, stationary bearings for said trunnions open at the top, a buffer disposed to support the fuse in open position and at a downward and forward inclination, a nember carried by the fuse and disposed forwardly thereof when the fuse is open, and a stick having a member adapted for cooperation with the fuse member for locking the fuse and the stick together when removing said fuse from its bearings.

In witness whereof, I hereunto subscribe my name this 23rd day of March, 1925.

FRED FARRELL. 

